Electronic devices mounted on bicycles, for example, for controlling the electronic gearshift and/or for acquiring, displaying, and controlling riding parameters and various functions, provide for the use of a power supply unit.
The power supply unit typically consists of one or more batteries typically connected in series, also referred to as a battery pack. The batteries used for such electronic devices are typically of a rechargeable type.
The nominal voltage and the capacity of a battery are correlated by a relationship that changes as the temperature of the battery changes. FIG. 22 shows an example characteristic curve, wherein the progression of the nominal voltage, expressed in V, and the capacity, expressed in mAh, of a battery is shown at temperatures of −20° C., −10° C., 0° C., room temperature, and 60° C.
As can be seen in the characteristic curve of FIG. 22, as the temperature decreases, the voltage and capacity values decrease, namely, the curves move towards the zero point. In certain cold conditions, as can be experienced in the cold seasons by the battery power supply unit of an electronic device, in particular mounted on a bicycle, the battery despite being charged is not therefore able to supply the current required by the load, or to maintain the required voltage. This therefore causes a degradation of the system performance. In order to best optimize the battery, it is therefore advantageous not to use it at low temperatures.
The technical problem at the basis of the present invention is to allow the power supply unit to also be used at low atmospheric temperature.